Phosphorus oxychloride → 7-Chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid

HRID 1759550Notes

Reaction equation

HRID 1759550 reaction equation
[CH2:1]([N:3]1[C:12]2[C:7](=[CH:8][C:9]([F:14])=[C:10](O)[N:11]=2)[C:6](=[O:15])[C:5]([C:16]([OH:18])=[O:17])=[CH:4]1)[CH3:2].P(Cl)(Cl)([Cl:21])=O>>[Cl:21][C:10]1[N:11]=[C:12]2[C:7]([C:6](=[O:15])[C:5]([C:16]([OH:18])=[O:17])=[CH:4][N:3]2[CH2:1][CH3:2])=[CH:8][C:9]=1[F:14]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178462626HCID 178462626, compound

Product 1

HCID 127908597-Chloro-1-ethyl-6-fluoro-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid

Procedure

A mixture containing 16 g of 1-ethyl-6-fluoro-7-hydroxy-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid and 160 ml of phosphoryl chloride was heated under reflux for 20 minutes with stirring. After evaporation of excess phosphoryl chloride under reduced pressure, the residue was triturated with ice-water and the mixture was stirred for 20 minutes. The resulting precipitate was collected by filtration, washed with water, dried, and recrystallized from acetonitrile to give 14 g of 7-chloro-1-ethyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid, m.p. 265°-267° C.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 20 minutes
  3. customAfter evaporation of excess phosphoryl chloride under reduced pressure
  4. customthe residue was triturated with ice-water
  5. stirringthe mixture was stirred for 20 minutes
  6. filtrationThe resulting precipitate was collected by filtration
  7. washwashed with water
  8. customdried
  9. customrecrystallized from acetonitrile

Sources & evidence

ORD record
ord-5bcfcff7b02641359db2adf231233302
Source dataset
uspto-grants-1982_07
Patent number
US04341784

Reaction notes

Loading…